1. Field of the Invention
This invention relates to a new process for producing the immunosuppressant agent, FK-506, utilizing the microorganism Streptomyces sp., (MA 6858) ATCC No. 55098.
2. Brief Description of Disclosures in the Art
In 1983, the U.S. FDA licensed cyclosporin, an extremely effective anti-rejection drug that revolutionized the field of organ transplant surgery. The drug acts by inhibiting the body's immune system from mobilizing its vast arsenal of natural protecting agents to reject the transplant's foreign protein.
As effective as that drug is in fighting transplantation rejection, it suffers drawbacks in causing kidney failure, liver damage and ulcers which in many cases can be very severe.
U.S. Pat. No. 4,894,366 and EPO Publication No. 0184162 to Fujisawa, hereby incorporated by reference, describe a new macrolide immunosuppressant, FK-506, which is reputed to be 100 times more effective than cyclosporin. The macrolide is produced by fermentation of Streptomyces tsukubaensis, a monotypic species of Streptomyces.
Processes or microoganisms for the production of these immunosuppressive agents, particularly FK-506, which may lack the side effects of cyclosporin, are constantly being searched for in the field.